JPH04214413A - Conjugate elastic yarn - Google Patents

Abstract

PURPOSE:To provide a novel elastic yarn free from hang-up, a drawback unique to' conventional polyurethane elastic yarns, capable of winding for a long time, excellent in the operability in the later processes such as yarn processing and knitting or weaving, also having highly excellent elastic properties and heat resistance. CONSTITUTION:The objective sheath-core type conjugate yarn with the core component consisting of a polyurethane-based elastomer and polyisocyanate compound and the sheath component a polyester elastomer.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention does not have stickiness, which is a serious drawback of polyurethane elastic yarns, and the yarn is extremely easy to handle in subsequent processes such as spinning, yarn processing, weaving, weaving, and dyeing. The present invention relates to a novel composite elastic yarn that has high heat resistance and has excellent heat resistance.

0002

[Prior Art] Polyurethane elastic yarns are used for a variety of purposes due to their excellent physical properties, but they suffer from agglomeration and resulting problems such as winding properties during spinning, various yarn processing, and operability in post-processes such as knitting and weaving. There is a problem. In order to improve these problems, countermeasures have been taken mainly from oil agents (for example, adding metal soaps and monoamines to oil agents, etc.), but these problems have not been completely solved.

[0003] Also, considering the case of spinning and winding, if the stickiness of the yarn is reduced, winding for a long period of time is likely to become impossible due to twilling, collapse of the winding, etc. This tendency increases as the winding speed increases (e.g. 500 m/min or more) and as the diameter of the bobbin decreases (e.g. 150 m/min or more).
m or less) becomes noticeable.

On the other hand, if the thread is made of adhesive, it becomes possible to wind the thread for a long time, but it becomes impossible to unwind the thread in the subsequent process, which causes serious trouble.

Next, we have already proposed a method for producing core-sheath type polyurethane elastic yarn in Japanese Patent Publication No. 61-14245 as a method for preventing sticking that does not involve using oil, but it is possible to produce a core-sheath type polyurethane elastic yarn at high speed and with a small diameter bobbin. There were some drawbacks in long-term winding properties, adhesive properties, and heat resistance.

On the other hand, polyester elastomers are known as another type of elastomer. Polyester elastomers are used in a variety of applications due to several excellent properties. Among thermoplastic elastomers, it has the advantage of being usable in a wide temperature range from high to low temperatures, and also has high load carrying capacity, high bending fatigue resistance, and excellent oil and chemical resistance. Similar to polyurethane, increasing the ratio of hard segments increases hardness and lacks elastic recovery, while increasing the ratio of soft segments increases softness and makes it rubber elastic, but heat resistance deteriorates.

[0007] In general, the elastic yarn obtained from this polyester elastomer must have a high proportion of soft segments in order to increase the elastic recovery rate, but this lowers the melting point and results in poor heat resistance.

[0008] Also, the yarn thus obtained has not yet been put into practical use as an elastic fiber, as it is very inferior to ordinary polyurethane elastic yarn.

As described above, elastic threads obtained from polyurethane elastomers and polyester elastomers each have major drawbacks and problems.

0010

[Problems to be Solved by the Invention] Therefore, the present invention does not cause sticking, which is a disadvantage peculiar to polyurethane elastic yarns, can be wound for a long time during spinning, and has extremely excellent elastic properties and heat resistance. The object of the present invention is to provide a novel composite elastic yarn having the following characteristics.

[0011]

[Means for Solving the Problems] In view of the current situation, the present inventors have made extensive studies to achieve the above object, and as a result, have arrived at the present invention. That is, the composite fiber of the present invention is characterized in that the core is a reaction product of a polyurethane elastomer and a polyisocyanate compound, and the sheath is a polyester elastomer.

The polyurethane elastomer which is the core component of the present invention contains a known segmented polyurethane copolymer, and the polyol component includes:
Polytetramethylene ether glycol or polycaprolactone polyester with a molecular weight of 500 to 6000,
Polycarbonate diol, polyhexamethylene adipate, polybutylene adipate, polyneopentylene adipate, polyhexamethylene/butylene adipate copolymer, polycarbonate/hexamethylene adipate copolymer, polyneopentylene/hexamethylene adipate copolymer, etc. Mixed diols containing at least one of these are preferred.

[0013] Also, as the organic diisocyanate component, p
, p'-diphenylmethane diisocyanate is preferred. In addition, glycols are particularly suitable as chain extenders;
, 4-bis(β-hydroxyethoxy)benzene and 1,4-butanediol are preferred.

On the other hand, as for the polyisocyanate compound which is the other component of the core component, the number of isocyanate groups contained in one molecule of the compound is 2.05 to 3, more preferably 2.1 to 2.8. Things are good.

If the number of functional groups is less than 2.05, the heat resistance of the composite yarn will decrease, and if it exceeds 3, the viscosity will increase, making handling undesirable.

The molecular weight of the polyisocyanate compound is preferably 400 or more, particularly 800 to 5,000.

The amount of NCO groups in the polyisocyanate compound is preferably in the range of 3.0 to 20% by weight.

Isocyanate components constituting the polyisocyanate compound include p,p'-diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), hexamethylene diisocyanate, etc., or these diisocyanates and low molecular weight polyols such as trimethylolpropane, Adducts with hexanetriol etc., mixtures of diisocyanates and the above trifunctional isocyanates, or crude MD
I, Crude TDI, etc.

On the other hand, examples of the polyol component include polyether diols or triols to which polyethylene glycol, polypropylene glycol, polytetramethylene glycol, propylene oxide and/or ethylene oxide and/or butylene oxide are added. Further examples include polyester diols such as polycaprolactone diol, polycarbonate diol, and polybutylene adipate, and polycaprolactone triols obtained by polyaddition of ε-caprolactone lactone with a triol such as trimethylolpropane.

Alternatively, low molecular weight diols such as 1,4-butanediol, triols and diols such as adipic acid
Polycondensation type polyester polyols consisting of basic acids are also preferred.

The proportion of the polyisocyanate compound is preferably 10 to 40% by weight based on the total weight of the core components.

As described above, a suitable crosslinked structure is provided in the core component, and the crosslinking density of this core component, which improves the heat resistance of the composite yarn, is such that only the core component has n
- When immersed for 24 hours in dimethyl sulfoxide to which 1/50N of butylamine is added, the weight of the insoluble portion is preferably 2% by weight or more.

Methods for dissolving the above-mentioned sheath components include, for example, ethers such as dioxane and tetrahydrofuran, phenols such as phenol, o-chlorophenol, and m-cresol, and halogenated carbonization of methylene chloride, chloroform, and tetrachloroethane. Hydrogen or the like may be used.

The polyester elastomer of the sheath component used in the present invention consists of a short chain ester part as a hard segment, that is, an aromatic dicarboxylic acid and a low molecular weight diol having a molecular weight of about 250 or less, and a long chain polyether part as a soft segment. and/or an elastomer composed of long chain polyester parts.

For example, aromatic dicarboxylic acids constituting the hard segment include terephthalic acid, isophthalic acid, bibenzoic acid, substituted dicarboxylic compounds having two benzene nuclei, such as bis(p-carboxyphenyl)methane, p -oxy(p-carboxyphenyl)benzoic acid, ethylene-bis(p-oxybenzoic acid), 1,5-
Examples include naphthalene dicarboxylic acid, and phenylene dicarboxylic acid, ie, terephthalic acid and isophthalic acid, are particularly preferred.

On the other hand, examples of low molecular weight diols having a molecular weight of about 250 or less include ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, cyclohexanedimethanol, resorcinol, and hydroquinone, with 2 to 8 being particularly preferred.
is an aliphatic diol containing 5 carbon atoms.

On the other hand, as the long chain polyether moiety constituting the soft segment, poly(1,2- and 1,3-propylene oxide) having a molecular weight of 500 to 6000 are used.
Examples include glycol, poly(tetramethylene oxide) glycol, random or block copolymers of ethylene oxide and 1,2-propylene oxide, and poly(tetramethylene oxide) glycol is preferred.

[0028] The long-chain polyester moiety includes polyaliphatic lactone diols such as polycaprolactone diol and polyvalerolactone diol, with polycaprolactone diol being particularly preferred. In addition, long-chain polyester moieties include aliphatic polyester diols, such as dibasic acids such as adipic acid, sebacic acid, 1,3-cyclohexanedicarboxylic acid, glutaric acid, succinic acid, oxalic acid, and azelaic acid, and 1,4-butanediol. , ethylene glycol, propylene glycol, hexamethylene glycol and other low molecular weight diols, and polybutylene adipate is particularly preferred.

Among these polyester elastomers, particularly, the hard segment is polybutylene terephthalate, and the soft segment is polybutylene terephthalate, and the soft segment has a molecular weight of 600 to 3.
A polyester/ether elastomer composed of 000 polytetramethylene glycol is preferred.

This is because polybutylene terephthalate, which has a very high crystallization rate, is used as the hard segment to improve moldability, which is the most important characteristic of thermoplastic elastomers. This is because by using soft segments, an elastomer with well-balanced properties such as low temperature flexibility, water resistance, and fatigue resistance can be obtained.

[0031] Furthermore, in order to improve weather resistance and heat aging resistance compared to polyester/ether elastomers, polyester/ester elastomers, that is, polybutylene terephthalate as the hard segment and polycaprolactone diol with a molecular weight of 600 to 3,000 as the soft segment, can be used. Particularly preferred are elastomers.

[0032] In order to use it for the same purpose as polyurethane elastic thread, elastic properties such as elongation and recovery are required.
In terms of hardness, it is preferable to have a JIS K 7215 hardness D of 60 or less and a DSC crystal melting point of 220° C. or less. This means that when it comes to manufacturing methods by melt spinning,
It is also preferable because it is necessary to spin at the same temperature as the polyurethane elastomer that is the core component during spinning.

[0033] In addition, it is also possible to appropriately contain a matting agent such as a light stabilizer, an antioxidant, a lubricant, or a titanium oxide in the polyester elastomer that is the sheath component. Modified elastomers containing additives such as additives, flame retardants, etc., or having such functions are also suitable.

The constituent components of both the core and sheath components have been explained above. Next, the core/sheath ratio will be described. If the ratio of the sheath component is large, the elastic recovery of the yarn obtained and its recovery from high temperatures will be improved. If there is not enough of it, or if there is too much of the core component, the sheath component will break and the core component will be exposed on the yarn surface, causing the core-sheath structure to break and making spinning impossible. Therefore, the core/sheath composite ratio is 70 in terms of cross-sectional area ratio.
A range of /30 to 99/1, particularly 80/20 to 99/1 is preferred.

In producing the composite elastic yarn of the present invention,
For example, the composite elastic yarn can be obtained by melt spinning using a known core-sheath composite spinneret.

In the above-mentioned core-sheath type composite spinning, even if the core component is an eccentric type core-sheath type composite elastic yarn in which the core component is eccentric from the center of the cross section perpendicular to the fiber axis of the composite elastic yarn, the core Although it may be a concentric core-sheath composite fiber in which the center of the cross section perpendicular to the fiber axis of the component and the composite elastic yarn are the same, concentric core-sheath composite fibers are preferred.

[0037]

[Effects of the Invention] As described above, the composite elastic yarn according to the present invention has
The core component is a reaction product of a polyurethane elastomer and a polyisocyanate compound, and the sheath component is a polyester elastomer, so there is no stickiness that is typical of ordinary polyurethane elastic yarns, and it is similar to ordinary nylon and polyester yarns. It has features such as being able to be rolled up. That is, high-speed winding is possible, winding is possible on a small-diameter bobbin, and the obtained yarn can be suitably used in subsequent processes as it is without the need for winding.

[0038] It also has the ability to be warped, which is impossible with ordinary spandex.

Next, regarding other physical properties such as heat resistance, the core component is a polymer crosslinked with a polyurethane elastomer and a polyisocyanate compound, so the thermal properties are good.

That is, if we consider the temperature-elongation creep curve, yarns that are not heat resistant creep quickly as the temperature rises, and conversely, yarns that are heat resistant do not creep even at higher temperatures. We have submitted an apparatus and method for non-contact measurement of the amount of creep, that is, the amount of elongation, in Japanese Patent Application No. 1-27103. When the yarn of the present invention is measured using this apparatus and method, it has a high temperature at 40% creep of 150° C. or more, which shows that it has very high heat resistance. Surprisingly, the heat resistance of the yarn containing only the sheath component was about 100° C., which shows how excellent the heat resistance of the composite elastic yarn of the present invention is.

Furthermore, polyurethane elastic yarns with such high crosslinking density that they have 2% by weight or more of undissolved matter when dissolved in n-butylamine/dimethylsulfoxide solution (1/50N), and polyurethane/polyurethane composite elastic yarns. In this case, the heat setting property becomes poor. On the other hand, the yarn of the present invention also has the advantage of excellent dimensional stability because it has good heat-setting properties even if the core component has a crosslinking density comparable to that described above.

[0042] Also, the adhesiveness of the core-sheath is strong, and it has advantageous properties such as no peeling observed in an abrasion test.

Therefore, it can be suitably used in fields where spandex is normally used (for example, socks, innerwear, swimwear, etc.). In particular, since the yarn of the present invention has excellent moist heat properties, it is also possible to use it in combination with polyester yarn.

[0044]

[Examples] Examples will be explained below, but the present invention is not limited to these examples.

Example 1 (1) Core component ■Polyurethane elastomer 1091.2 parts of dehydrated polyhexamethylene adipate diol with a hydroxyl value of 59.1 and 94.4 parts of 1,4-butanediol were mixed in a kneader with a jacket. Prepared in
After sufficiently dissolving with stirring, the temperature was maintained at 85°C, and p,p'-diphenylmethane diisocyanate 41
4.2 parts were added and reacted. The obtained reaction product was taken out from the kneader and formed into pellets using an extruder. This molded article had a relative viscosity of 2.09 in dimethylformamide at 25°C.

■Polyisocyanate compound A molecular weight 10
00 polycaprolactone diol 14.1 mol, molecular weight 1250 polycaprolactone triol (plac
cel 312: manufactured by Daicel Chemical Industries, Ltd.)
14.1 mol (polyol calculated functionality 2.5)
P,P'-diphenylmethane diisocyanate (MD
I) 71.8 moles were reacted in a conventional manner to obtain a viscous compound. The NCO% of this compound A was 6.2% by weight.

Further, 1 mole of polycaprolactone diol having a molecular weight of 850 was reacted with 2 moles of MDI to obtain polyisocyanate compound B. The NCO% of this is
It was 6.2% by weight.

■Polyisocyanate compound C A mixture of a 2-functional polyol and a 3-functional polyol with a molecular weight of 220
0 Polylite OD-X-106 (manufactured by Dainippon Ink Co., Ltd.: number of functional groups: 2.3) 1.3 mol and MDI 4.
A viscous compound was obtained by reacting with 5 mol. The NCO% of this was 6.3% by weight.

(2) Sheath component Hytrel 4047 (Shore hardness D40: manufactured by DuPont-Toray), which is a polyester/ether elastomer, was used as the sheath component.

When the polyurethane elastomer as the core component is melted, one of the polyisocyanate compounds A is injected through the feeding device, and both components are kneaded in a kneading device having 30 stationary kneading elements to form the core component, On the other hand, the above-mentioned sheath component was melted by an extruder, introduced into a concentric core-sheath composite spinneret (nozzle diameter 1.0 mm), and spun into a paper tube bobbin with an outer diameter of 90 mm at a winding speed of 600 m/min. A composite elastic yarn of 40 denier was obtained. Note that a polyether emulsion oil agent was used as the oil agent. The results are shown in Table 1.

[Table 1] Note 1) Heat resistance: Whether or not the material melts and cuts when placed in a hot air dryer at 190° C. for 1 minute in a 30% elongated state, and is rated ◎ if it does not melt. Note 2) Creep temperature: 40 in the temperature-elongation creep curve at a load of 12.5 mg/d and a heating rate of 70°C/min.
Measure the temperature at the time of % elongation. Note 3) Unwinding coefficient: urethane thread wound into a bobbin shape
When unwinding at a speed of 0 m/min, the ratio of the surface speed of the bobbin to the surface speed of the winding roller when it becomes impossible to unwind the yarn due to sticking on the surface of the bobbin. Note 4) Winding time: The time that can be rolled up without slipping or collapsing. It was shown to.

Comparative Examples 1-3 and 1-4 show the results of yarns with a core-sheath structure obtained using the above-mentioned polyurethane elastomer instead of Hytrel as the sheath component using the same equipment and conditions.

Incidentally, the oil agents of Comparative Examples 1-3 and 1-4 were NC
The amount of amino-modified silicon as O deactivator was 0.0, respectively.
A material mainly composed of dimethyl silicon added with 3% and 5% was used. (No sticking was observed with the oil containing 5% amino-modified silicone.)

Comparative Examples 1-5 use polyisocyanate compound B.

[0054] The yarns in Table 1 have a core component of 1/50N.
-n The amount of undissolved matter when dissolved in a butylamine/dimethyl sulfoxide solution was 2% by weight or more in all cases except for Comparative Examples 1-5. In Comparative Example 1-5, it was 1.4% by weight.

From Table 1, it can be seen that as the composite ratio increases, that is, as the proportion of the core component increases, the heat resistance of the resulting composite elastic yarn increases.

Comparative Examples 1-3 and 1-4 Comparative Example 1-3
If the stalemate is caused as in 1-4, it becomes possible to unwind the paper.
When the unraveling coefficient reached 1.00, that is, when the stickiness between the yarns disappeared, curling occurred in 20 minutes.

It is also found that increasing the amount of polyisocyanate compound increases heat resistance.

Comparative Example 1-5 shows that when the number of functional groups in the polyisocyanate compound is 2.0, the creep temperature, that is, the heat resistance is poor.

The yarn of the present invention was free from adhesion and had a good winding shape. Moreover, no peeling of the core-sheath portion was observed.

Example 2 Spinning was carried out in the same manner as in Example 1 except that the polyisocyanate compound in the core component was changed from A to B. This result is shown in Table 2.

[Table 2] It was shown to.

The amount of undissolved parts in the core components of Comparative Examples 2-1 and 2-2 was 0% by weight, and that of all the inventive examples was 2% by weight or more.

From Table 2, it can be seen that as the composite ratio increases and as the amount of polyisocyanate compound increases, the heat resistance improves.

Claims (8)

[Claims] 1. A composite elastic yarn characterized in that the core is a reaction product of a polyurethane elastomer and a polyisocyanate compound, and the sheath is a polyester elastomer. 2. The composite elastic yarn according to claim 1, wherein the polyisocyanate compound has a functional group number of 2.05 to 3. [Claim 3] 4 in the temperature-elongation creep curve
The composite elastic yarn according to claim 1, which has a temperature at 0% elongation of 150° C. or higher. 4. When the core component after dissolving the sheath component is dissolved in dimethyl sulfoxide to which 1/50N of n-butylamine compound is added, there is an undissolved portion of 2% by weight or more. composite elastic yarn. 5. The composite elastic yarn according to claim 1, wherein the adhesiveness between the core component and the sheath component is enhanced by a polyisocyanate compound in the core component. 6. The composite elastic yarn according to claim 1, wherein the proportion of the polyisocyanate compound in the core component is 10 to 40% by weight based on the total weight of the core component. 7. The composite elastic yarn according to claim 1, wherein the core-sheath composite shape is concentric or eccentric. [Claim 8] The cross-sectional area ratio of the core and sheath is 70/30 to 99.
2. The composite elastic yarn according to claim 1, wherein the elastic yarn has a diameter of /1.